“The preliminary analysis shows we are are probably talking about explosives of the type used, among other things, for industrial purposes, for example for demolition work or similar tasks,” Jørgen Bergen Skov, chief inspector of the Copenhagen Police, said in a press release issued on Friday afternoon.
Skov said that the explosives had been placed about 60cm from the entrance of the agency.
The blast on Tuesday night left the agency's metal front entrance bent completely out of shape and shattered almost all of the windows on the facade.
“This is a case that we are taking very seriously and that is our main priority,” Skov continued. “We are confident and are pursuing several concrete clues, but for the sake of our investigation I cannot go into further detail about these.”
Skov said that 123 people had left eyewitness statements and other testimony, either by phone or by dropping into a mobile police station set up at Nordhavn Station.
“It has been important for the investigation, and if there is still someone out there who has knowledge and has not yet been in contact with us, then our phones are open around the clock,” he said.
Peter Hald, a researcher at Aarhus University, said his guess was that the explosives had been brought into Denmark from overseas.
“I'm convinced it's come from abroad. Norway or Sweden is my best guess, but the Balkans are my second best guess, as they have been major suppliers of weapons and explosives,” he told Danish state broadcaster DR.
Hald said that the rocky landscapes found in Norway and Sweden meant there was a greater need for explosives in road and house construction than in Denmark.
According to police in Malmö, across the Øresund Bridge from Copenhagen, industrial explosives have over the past year been used frequently in gangland attacks, replacing the powerful bangers and hand grenades used in previous years.